Fuse



AprilL 18, 1939- c. L.. MATTHEWS ET AL 2,154,588

FUSE

2 Sheets-Sheet 1 F I G2.

Filed Feb. l0, 1936 April 18, 1939- c.,| MATTHEWS ET A1. 2,154,688

FUSE

Filed Feb. lO, 1936 2 Sheets-Sheet 2 .5 Among the several Patented Apr.18, 1939 PATENT oFElcE 2.15am I rusa cima l.. Matthews; si. Louis, carlE. Mosley,

Richmond Heigh St. Louis,- Mo.,

ts, and Theodore Birkenmaier, signers to W. N. Matthews Corporation, St.Louis, Mo., Missouri a corporation of Application February lo, 1936,serial Nn. 63,098`

7- Claims.

This invention relates to fuses, and with regard to certain more specicfeatures, to fuses having means for separating the fuse ends uponblowing. I

objects of the invention may be noted the provision of a simple andeco-4 nonlical form of fuse cutout which is adapted to be connectedbetween a transformer secondary or the like and adjacent apparatuswithout a l `special mount or enclosure; the provision of a device ofthe class described, which despite its lack of mounting or covering, ispositively safe and reliable in opening the circuit, without thepossibility of an accidental non-fused reclosure of the circuit throughthe burned fuse link; the provision of a vfuse cutout which may beuniversally used in connection with vvarious apparatus; and theprovision of a device of the class described having a fuse-link terminalwhich prevents undesirable destructive action on the link when making afastening. Other objects will. be in part obvious and in part pointedout hereirlafter.

The invention accordingly comprises the elements and combinations ofelements, featuresy .of construction, and arrangements of parts whichwill be exemplified in the structures hereinafter described, and thescope of the application of which will be indicated in the followingclaims.

In the accompanying drawings, in whichis illustrated one of variouspossible embodiments of the invention, l Fig. 1 is a side elevationlshowing one application of the device; 35 Fig. 2 ls an enlarged verticalsection of one form of the invention;

Fig. 3 is a fragmentary right-side elevation of Fig. 1 but showing afuse pulling device in open position and without a fuse link therein;Fig. 4 is a view similar to Fig. 1 showing the apparatus in blowncondition;

Fig. 5 is a cross section taken on line 5-5 of Fig. 2;

Fig. 6 is a side elevation, parts being broken 45 away, and showing analternative form and application of the invention; and,

Fig. 'l is a side elevation showing another application. Similarreference characters indicate corre- 50 spending parts throughout theseveral views of the drawings.

Referring now more particularly to Fig. l, there is shown at numeral I,for example, a secondary outlet tap of4 a transformer which it isdesired,`

55 through-a fuse, to electrically connect with a (Cl. '20o-117) wiresuch as shown at 3. Itis to be understood that the `invention may beapplied directly to the secondary transformer studs where taps are notused and to other connections than secondary taps or studs oftransformers, and that it has general utility in the electrical field,both for high and low`=voltages. For instance, in Fig. 6, the device isshown attached to a transformer stud 2, and in Fig.7 it is shownelectrically connecting line wire sections 4 and 6 which aremechanically joined by the strain insulator 8. In this" case an insertwire III may be used. As will be clear from the following speciiication,ous fuse links adaptable for primary and secondary applications. Otherapplications may be thought of with the above as examples.

-At numerals 5 and 9 are shown deformable conducting terminals composedof material such as heavy bendable (but in the drawings nonilexible)copper wires, which are initially made straight and so delivered to theuser. The user .then bends and/or cuts off portions of .these terminals5 and 9 to suit his needs, and, as illustrated in the drawings, they`have been bent to suitable positions. Thus an electrical connection maybe made by means of a connector 1 of known type, to any size ofconductor wire which is within the range of the connectors 1. As shownin Fig. 6, bending may not be necessary.

It is to be understood that the wires 5 and/or 9 may be flexible andthat the term deformable is meant to be genericto the terms flexible andbendable".

Between the terminals 5 and 9 is located the cutout per se, but it is tobe understood that it and the terminals 5 and 9 form a unit whendelivered to the customer, with the WiresA 5 and 9 preferably, thoughnot necessarily straight and solid, but as above forecast they may beflexible wires. v

In the form of theinvention shown in Fig. 1, the upper terminal 5. formsa rigid extension from an upper terminal socket I3 within which isheldthe upper end of an insulating, expulsion tube I5. The terminalsocket I3 has an upper inlet I1 which is in alinement with the openingI9 of the insulating tube I5. The element I3 is threaded about saidopening Il to accommodate a cap 2I which may be removed to permitinsertion of a fuse link 23, the .head`25 of which rests upon the upperend of the element I3 and which is clamped in place' by replacement ofthe cap 2|.

The lower end of the tube I5 passes through the device will accommodatevari 1n turn connected to a second conducting portion 3| which connectswith The wires 5 and 9 may be said head 25. soldered or sweated in theirsockets, as shown in Fig. 2, or be riveted,l

as shown in Fig. 6.

The socket member 24 extends, as shown at numeral 33, to form a supportfor a pin 35. The pin 35 serves as a pivot for an arm 31 which has anopening 39 therein for accommodating passage therethrough of theconducting portion 21 of thev link 29. The arm 31 may swing on the pin35 from the position shown in Fig. 4 clockwise to that shown in Figs. 1and 2, vin winch latter position said opening 39 is in Substantialalinement or adjacent to the opening I9 through the tube l5.

The underside of the arm 311s provided with a plurality of guiding lugs4| for positioning the conductor 21 under and on the arm 31. Theconductor is thus led around the rear end of the arm to a position oversaid extension 33. Here `the conductor 21 is wrapped about a stud andthreaded (Fig. 2).

A thumb nut 45 is threadedto the upper threaded portion of the stud 43and is provided with a round counterbore which clears the corners of thesquare base of said stud to form a skirt 41. This skirt is externallygrooved as at 48. A washer 49 has ears 5| which are crimped into thegroove 48.

is provided a rotatable nut 45 which is adapted to drive the washer 49down on the end of the conductor 21 without rotation of the washer.'I'he washer can slide onthe square shank but cannot rotate, while thenut c an both'rotate and move endwise. There is relative rotary motionduring adjustment between the ears 5| and the ange 53 but no relativelongitudinal motion. Thus there is provided means whereby the ends ofthe component wires in the iiexible wire 21 only compress upon making ajuncture, rather than twist and fray.

A spring 51 is wound about the pin 35 and has one arm 59 reacting underthe extension 33 and another arm 6| reacting over the lever 31, thus ltopush the lever downwardly.

To prepare the device for operation, the cap 2| is unscrewed and thelink 23 threaded through the opening I1. The cap 2| is then reappliedand the head 25 of the link thus'held in electrical contact with thesocket |3.- The upper conductor 3| extends into the tube I5, the lattersurrounding the fusible portion 29. The lower, flexible conductingelement 21 extends downward, from the lower open mouth of the tube l5,and is threaded through the opening 39,`around the lever 31 and clampedby rotating the thumb screw 45. During this threading and clampingoperation, the lever 31 is turned upwardly to the position shown inFigs. 1 and 2, thus tensioning the spring 51 and causing the lever 31 totension the fuse link.

Upon blowing of the link 23, under heavy overfllsible portion 29,'

load conditions, the gases formed by the fusion at the fusible portion2l will more or less violently eject the conductor 21. The lever 31 willmove coimterclockwise' until the rear set of lugs 4| strikes the back ofthe extension 33, thus limiting the counterclockwise motion of to theposition shown in Fig. 4. for the exible conductor 21 to whip upwardlythrough an arc, is limited to the small dotted-line circle B shownaround center Y, that is it cannot whip upwardly and into contact withthe live member 5, or parts associated therewith along the arc A oncenter The above construction is quite different from those heretoforeemployed, in which the means for whipping out the lower or flexibleconducting element of the fuse have, in effect, had the conductingelements swing around a higher center somewhere near the center X (Fig.4), thus also leaving a greater length of flexible whipping wire whichcould swing up on the higher center and reach the live portions of thecircuit. In short, this invention provides a means for lowering thecenter of swing of the flexible, separatedv conducting portion of thelink after blowing. It also reduces the length of the portion of 21which swings. In Fig. 4, the radius of arc A is the old free length ofswing on center X; and the radius of B is the new limited free length ofswing on the lowered center Y.

It is to be understood that if the overload is of the so-called draggingvariety,l lthen the expulsive feature may not come into operation andthe-flexible link will merely be pulled downwardly by the arm 31,without any tendency in any event to again swing upwardly. swingingradius is still limited which is advantageous. It will be seen from thisthat the invention is serviceable, both in cases where overloads providethe expulsionaction and where they db not.

Another feature of the invention, when used under any conditions, isthat the position of the arm 31 provides a visible indication as towhether functioned, and saves time in the location of blown out fuses.For instance, in the case of Fig. 4, it is quite cle'ar that the fusehas blown. l

It is to be understood that although the invention is primarily usefulfor unenclosed'fuses, it is also useful in connection with box type orenclosed fuses, because it prevents any excessive length of fuse linkfrom whipping out and swinging from the open lower end of contact withoutside wires or the like.

In view of the above, it will be seen that the several objects of theinvention are achieved and other advantageous results attained.

As many changes could be-made in carrying out the above constructionswithout departing from the'scope of the invention, it is intended thatall matter contained in the above description or shown in theaccompanying drawings shall be interpreted as illustrative and not in alimiting sense.

We claim:

1. A fuse comprising spaced contacts, a fuse link having a fusibleportion andv including a portion electrically connected between saidcontacts and having a turned portion thereand means pivoted to one ofsaid conbetween, tacts and having an opening through which said fuselink is passed at said turned portion and between its points ofconnection with said contacts,

However the freethe box and into said link being permanently attached tothe fuse at a point below the fusible portion of the link,

2. A fuse comprising spaced contacts, a iuse link having a iiexibleportion held to said con`- tacts and extending therebetween, aninsulating tube between said contacts and surrounding a portion of saidlink, ysaid link extending from the tube, means pivoted to one of saidcontacts and having an opening adapted to be positioned adjacent thetube outlet in one position ci said pivoted means, the ilexible portionof said link being threaded therethrough, means normally tensioning saidpivoted means to withdraw a portion of the fuse link from the tube uponblowing of the fuse, and limiting stop means between said pivoted memberand the contact to which it is pivoted, whereby upon withdrawal ci' saidilexible portion, the center of whip of the same is moved away from thepivot contact.

3. A fuse comprising spaced upper and lower contacts, a fuse link havinga exible portion electrically connecting said contacts, an insulatingtube joining said upper and lower contacts and surrounding a portion ofsaid link and having an opening below the lower contact, said linkextending irom said lower opening, an arm pivoted to said lower contactand having an opening adapted to be swung adjacent to the lower openingin the tube, said link being threaded through said arm opening whenconnected to at least one of said contacts, spring reacting meansbetween said arm and said lower contact adapted normally to tend towithdraw the fuse link from the tube, and stop means between said'armand said lower contact adapted upon blowing of the fuse to maintain thesubstantialcenter of whip of the flexible portion of the link to a pointsubstantially below the lower contact.

4. A fuse comprising spaced upper and lower contacts, a fuse link havinga ilexible portion electrically connecting said. contacts. an insulatingtube joining said upper and lower contacts and surrounding a portion oisaid link and having an opening below the lower contact, said linkextending from said lower opening. an arm pivoted to said lower contactand having an opening adapted to be swung adjacent to the lower openingin the tube, said link being threaded through said ann opening whenconnected to at least one of said contacts, spring reacting meansbetween said arm and said lower contact adapted normally to tend towithdraw the fuse link from the tube, stop means between said arm andsaid lower contact adapted upon blowing of the fuse to maintain thesubstantial center of whip of the flexible portion of the link to apoint substantially below tensions comprising cylindric conductors whichare adapted to be bent and cut in the field but which are strong enoughto support the fuse in the circuit, the spaced contacts, mechanism andextensions forming a rigid unit when mounted.

6. A fuse comprising spaced contacts, a fuse link held to said contactsand extending therebetween, said link having a flexible portion, aninsulating tube between said contacts and surrounding a portion of saidlink, said link extending from the tube and being turned backexternally, means pivoted to one of said contacts and having an openingadapted to be positioned adJacent the tube outlet in one position, saidlink passing through said opening adjacent the region where it is turnedback, and means biasing said pivoted means to withdraw a portion of thefuse from the tube upon blowing'oi the fuse, said link being permanentlyattached to the contact which supports said pivoted means.

7. An expulsion-tube current interrupter comprising a tube of insulatingmaterial, a fuse link within the tube consisting of a small fusibleportion and a larger ilexible portion, an arm hingedly mounted near oneopen end of the tube with a swinging end movable from closed-circuitposition at the tube to open-circuit position away from the tube, and aring opening at the swing end of the arm to receive the flexibleconductor.

CLAUD L. MATTHEWS. CARL E. MOSLEY. THEODORE BIRKENMAIER.

